These days I don't use music so much because I found it actually distracts me as a GM, but when I dd I mostly ran horror games and would often use the 92 Dracula Soundtrack, the Hellraiser Soundtrack, Danse Macabre, Henry Purcell harpsichord suites, The ennui Morricone Hamlet soundtrack (this is really good gaming music in general), the Ennio Morricone Wolf soundtrack (he has a lot of interesting stuff from this period that isn't as iconic as his 60s and 70s work, but worth checking out...the Mission is another good one of his from this era). I actually liked the Henry V soundtrack and the Frankenstein soundtrack by Patrick Doyle as well. I could never do anything with lyrics as that would distract me. Eventually I noticed myself getting overly distracted by melodies so stopped with music (I also found that in most of my groups about half said they liked the music and half said they didn't want music).